As adverbs the difference between overall and eventually
is that overall
is generally; with everything considered while eventually
is in the end.
As an adjective overall
is all-encompassing, all around.
As a noun overall
is (british) a garment worn over other clothing to protect it; a coverall or boiler suit a garment, for manual labor or for casual wear, often made of a single piece of fabric, with long legs and a bib upper, supported from the shoulders with straps, and having several large pockets and loops for carrying tools.